Keep new car to 50mph for 1st 500 miles?
May 19, 2006 7:19 AM   Subscribe

I just bought a new car. I seem to remember hearing that you should keep the speed to, say, 50 mph, for its first couple hundred miles - something to do with tires or brakes... Is that right? Do I need to do this?
posted by crepeMyrtle to Travel & Transportation (15 answers total)
Best answer: Read the manual that came with your car -- it's likely the exact details are spelled out. Personally with the last two cars I got the manual suggested no rapid acceleration and no hard braking for the first 600 miles. Basically drive it nice and slow for the first month. Freeway speeds are ok if you get up to speed gently.

If I recall the thinking is the engine parts are all still new and you don't want to do anything to jar a bit of metal into it that can cause some long term damage.

Also, be sure to check the manual on the first oil change and stick to that. My last car came from the factory supposedly with special oil for the first run and I had to keep it in for 5,000 miles before changing.
posted by mathowie at 7:26 AM on May 19, 2006

Response by poster: yeah, I know: RTFM :o). I will - just thought there might be a general consensus of knowledge that I could add to the manual. Thanks for the reminder about the oil change instructions. I'm used to older cars which need oil on a regular basis (my 95 Saturn, which I love, sucks it down pretty often).
posted by crepeMyrtle at 7:32 AM on May 19, 2006

When I got my car, I was told by the guys at the dealership to alternate speeds for the first 500 miles. I could do some slower city driving and some highway driving over 50 mph, but they didn't recommend that I took it on the 400 mile all-highway trip I was planning for that weekend.

I was also told no hard braking for the first 500 miles, which seems silly to me since you only brake hard when you have to - I wasn't going to rear-end someone to protect my new brakes if I was in that situation.

When I mentioned the 500 mile rule to a few people they all seemed familiar with it, but that's just anecdotal, it may not be the "general consensus." You know, check your manual.
posted by amro at 7:40 AM on May 19, 2006

took = take
posted by amro at 7:41 AM on May 19, 2006

"...which seems silly to me since you only brake hard when you have to..."

Ah, if only there were more drivers like you around here.
posted by solotoro at 7:48 AM on May 19, 2006

Best answer: Lots of misinformation out there on this subject.

At least for performance cars, the general concensus seems to be 500-1000 miles, and keep the RPMs in the lower range (like say below 4k, don't redline it out of the dealership parking lot)

Also, as another poster above indicated, vary your RPMs, and don't use cruise control for the first 1000 miles, (a long road trip is fine, just vary the throttle alot and make your passengers car-sick)

as far as bedding in your brake pads, here is a good explanation of that process.
posted by freq at 7:54 AM on May 19, 2006

I was going to say the same thing matt did, but I guess that is because we are both Honda owners.

No "jackrabbit" accelleration, and when at highway speeds don't use the cruise control. In other words, don't stick at the same speed level. That's what my manual and my salesperson said.
posted by terrapin at 8:08 AM on May 19, 2006

Response by poster: Thanks for suggestions. I'm heading out to the bay this weekend (200 mile roundtrip), and will vary my speed, which is pretty much how I drive anyway. I'll be on back roads (35mph) and blue highways (60mph) and little towns along the way, which will necessitate some braking (esp for fresh veggie stands). What I've got is a new Mazda3 and it's got so much more power than I'm used to (see above - the 95 Saturn). Can't wait :o)
posted by crepeMyrtle at 8:27 AM on May 19, 2006

My girlfriend and I took our brand new Ford Escape on a 3000km (1800 mile) road trip two days after we got it. We didn't baby it in any way. 15,000 km's later everything's golden.

For what that's worth.
posted by davey_darling at 9:05 AM on May 19, 2006

The manual that came with my car said "Your Elantra doesn't need a break-in period, but if you want to 'break it in' anyway, here's what you can do" and proceeded to list all the usual stuff. This confused me slightly but I just drove the car as I normally would, and it's been fine.

I have also heard that if you have disc brakes, you should "glaze" them by accelerating to about 70, then braking hard to around 20 (not actually stopping) and repeating this a few times. By doing hard braking but not actually stopping, you heat the brakes up enough to break them in but don't get any bumps in the brake surface (as you might if you actually came to a stop and the brake surface cooled while the calipers were clenched). My car's manual didn't say anything about this, however, and YMMV.
posted by kindall at 9:09 AM on May 19, 2006

This is the best piece I've ever read on running in engines.

Actually that whole section of the site is excellent reading, even if you have no desire at all to own a 500cc single-cylinder Indian motorcycle.
posted by flabdablet at 9:41 AM on May 19, 2006 [1 favorite]

I was very surprised the last outboard engine (4 stroke) that I bought essentially had no break in procedure -- just 2 hours of variable speeds and slower acceleration. I was lead to believe this was normal for most modern engines, whatever their application.
posted by Rumple at 11:06 AM on May 19, 2006

I'll chime in with the same info, RTFM, but with my car (Matrix) it was 1000km (600miles or so) of no hard accelerating, no letting the revs up too high (shift around 3000 RPM) and no constant speed.

This is much better than it used to be, replacing an engine in a '92 Stanza it was 5000 miles (yes miles) break-in reccomended.

As with any complicated machinery, fits aren't perfect, that is why there is a period when you don't want to push too hard, allowing the (very very small) protruding bits to wear away where they have to etc. Quality control has greatly improved over the years, hence the 600 / 1000 mile rule instead of the old 5000 miles. Also, you no longer have to remove the oil & transmission fluid after 200 miles to clean out all the metal bits (a bit longer ago!)

Enjoy your new car!
posted by defcom1 at 12:12 PM on May 19, 2006

The handbook for my Mazda3 says much the same as kindall's Elantra.

Section 4-7 in my (Oz) handbook:
"No special running-in is necessary, but a few precautions in the first 1000km (600 miles) may add to the performance, economy, and life of your Mazda."

And goes on to say what everybody else has already said - be nice to it, dont rev hard, vary the revs, don't brake hard, etc. Sounds like your little trip is just what the doctor ordered.

Having stepped down to a 2.3L Mazda3 from a 4.2L Ford, I can only wonder how bad a Saturn is if a Mazda3 has "so much more power"!

Enjoy the corners - the way the back end just sits in and grips harder on the even tightest turns is magical, compared to most small FWD cars.
posted by Pinback at 6:37 PM on May 19, 2006

The manual for my 2006 Chevy Cobalt (which I've had all of 3 weeks) says to try not to drive any one set speed for the first 500 miles.
posted by IndigoRain at 11:25 PM on May 19, 2006

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